What this checks
Spam filters look up the domains in a message (the From address and every link) against domain blocklists. A listing on any of the three checked here is enough for many receivers to send your mail to spam, or to refuse it outright.
- Spamhaus DBL lists domains seen in spam, phishing and malware. It is the most widely used domain list, and a listing here hurts the most.
- SURBL lists domains that appear in unsolicited mail and abuse, with separate categories for phishing, malware and cracked sites.
- URIBL lists domains found in spam message bodies. Its "grey" category marks bulk senders and is shown as a note, not a listing.
How to read the result
Not listed means the list answered and has no entry for the domain. Listed comes with the list's own reason code. Not checked means the list refused or failed to answer; it never means "listed". Every list is tested against its published test entry before the tool trusts its answer about your domain.
If your domain is listed
- Stop sending from the domain, including scheduled follow-ups. Removal requests made while spam is still flowing are usually refused.
- Find the cause. For cold outreach it is usually volume that ramped too fast, a list with many invalid addresses, or a link to a domain that is itself listed. Check every domain your emails link to, too.
- Fix authentication with the deliverability checker and verify your list with the email address checker.
- Request removal through the link on the result. Each list has its own form; there is no single delisting service.
- Restart at low volume and ramp up slowly.
To stay off the lists, keep bounces low and volume steady: the cold email calculator shows how many mailboxes and domains a goal takes, so no single mailbox carries too much.